Error in Extent Report Generation: NoClassDefFoundError

Web Testing
1

I am encountering an error when executing my test cases in Katalon Studio 10.3.2.0, specifically related to the generation of the Extent report. Below are the relevant details and the error that appears in the logs:

Execution Context:

  • User: Ramiro Marcos Morales

  • Project: Agenda

  • Operating System: Windows 11 64-bit

  • Katalon Version: 10.3.2.0

Execution Log:

2025-10-30 15:03:52.929 INFO  com.kms.katalon.core.util.KeywordUtil    - Start generating Extent report folder from: C:\Users\rmarcosm\AppData\Local\Temp\20251030_150219__7803238481769332424...
2025-10-30 15:03:53.378 ERROR c.k.k.core.context.internal.TestHooker   - ❌ org.codehaus.groovy.runtime.InvokerInvocationException: java.lang.NoClassDefFoundError: com/kms/katalon/core/reporting/basic/reporting/ReportWriterUtil

Error Description:
The error NoClassDefFoundError indicates that a necessary class is missing, which Katalon is trying to use when generating the Extent report. I would like to understand why it is attempting to generate a report when it hasn’t been explicitly indicated in the script, and how I can resolve this issue.

Steps I Have Tried:

  1. Verifying the configuration of the Extent Reports plugin.

  2. Reviewing project dependencies.

  3. Checking for errors in the test scripts.

I would appreciate any advice or solutions you can provide to help resolve this issue.

2 Likes
2
  1. Reinstall the Extent Reports Plugin
  • Uninstall the plugin via Katalon Studio and remove any manually added Extent Reports listeners.
  • Reload plugins using “Profile > Reload Plugins” in Katalon Studio.
  • Reinstall the latest Extent Reports plugin compatible with your current Katalon version from the Katalon Store.​
  1. Update Listeners/Custom Code
  • If you are using custom listeners, ensure they use only APIs/classes available in your version of Katalon Studio. Remove any references to deprecated or missing internal classes.
  1. Check for Katalon Version Compatibility
  • Review the Extent Reports plugin documentation and release notes to confirm version support. Update to a fully compatible plugin and Katalon Studio pair.​
  1. Clean Project Workspace
  • Close Katalon, delete the bin/, Libs/, and temp folders in the project directory, and reopen to let Katalon rebuild dependencies.
  1. Plugin Scope
  • Note that the Extent Reports plugin only generates reports for “Test Suite” (not for individual Test Cases)
3

I tried all the options mentioned, with a new project and even with an older version of Katalon, but it still doesn’t work. What other option would you suggest?

4

The Extent Reports integration plugin uses the package com.katalon.extent.report.ExtentReport.

Unfortunately the plugin does not disclose its source code. So nobody except Katalon can check how this plugin is implemented. Neither do I.

Presumably the Extent Reports product has nothing to do with the string com.kms.katalon.core.reporting.basic.reporting.ReportWriterUtil.

@ramiromarcos should check his/her test scripts and investigate why it wanted to find the com.kms.katalon.core.reporting.basic.reporting.ReportWriterUtil class.

1 Like
5

can you share error logs for each options you had tried

1 Like
6

I found the origin of the class:

It is a part of the katalon-studio-basic-report-plugin.

Starting from v6.1.5, the Report feature is no longer available on Katalon Studio, users need to download this plugin to continue using.

I remember that nobody welcomed this idea. Why do we have to bother installing a plugin for the mandatory feature: “the basic report”. I believe nobody used this plugin; so Katalon dropped it.

But now @ramiromarcos requires it with v10.3.2. I wonder why. I guess @ramiromarcos has a custom Groovy class (keyword?) which depends on the com.kms.katalon.core.reporting.basic.reporting.ReportWriterUtil. I suppose, @ramiromarcos have to modify his/her class.

If @ramiromarcos could install the plugin into the v10.3.2, the ClassNotFoundException might be resolved.

1 Like
7

See the Katalon Studio API Javadoc for the class com.kms.katalon.core.reporting.ReportWriterUtil:

This class is included in all version of Katalon Studio including the latest v10.x.

If you compare the 2 classes com.kms.katalon.core.reporting.ReportWriterUtil and com.kms.katalon.core.basic.reporting.ReportWriterUtil, you will find that these are almost identical. They implements almost the same set of methods.

I guess that the missing com.kms.katalon.core.basic.reporting.ReportWriterUtil was created, years ago, by simply copy&pasting the original com.kms.katalon.core.reporting.ReportWriterUtil into a new source with another package com.kms.katalon.core.basic.reporting.

So I think that @ramiromarcos should try changing his/her custom code:

OLD:

import com.kms.katalon.core.basic.reporting.ReportWriterUtil;

NEW

import com.kms.katalon.core.reporting.ReportWriterUtil;

Then, I think, the “NoClassDefFoundError” will disappear, though @ramiromarcos may encounter some new errors. Just try and see.

1 Like
8

kindly let us know on your issue resolution